A person’s chronotype reflects individual variability in diurnal rhythms for preferred timing of sleep and daily activities such as exercise and food intake. The aim of this review is to provide an overview of the evidence around the influence of chronotype on eating behaviour and appetite control, as well as our perspectives and suggestions for future research. Increasing evidence demonstrates that late chronotype is associated with adverse health outcomes. A late chronotype may exacerbate the influence of greater evening energy intake on overweight/obesity risk and curtail weight management efforts. Furthermore, late chronotypes tend to have worse diet quality, with greater intake of fast foods, caffeine and alcohol and lower intake of fruits and vegetables. Late chronotype is also associated with eating behaviour traits that increase the susceptibility to overconsumption such as disinhibition, food cravings and binge eating. Whether an individual’s chronotype influences appetite in response to food intake and exercise is an area of recent interest that has largely been overlooked. Preliminary evidence suggests additive rather than interactive effects of chronotype and meal timing on appetite and food reward, but that hunger may decrease to a greater extent in response to morning exercise in early chronotypes and in response to evening exercise in late chronotypes. More studies examining the interplay between an individual’s chronotype, food intake/exercise timing and sleep are required as this could be of importance to inform personalised dietary and exercise prescriptions to promote better appetite control and weight management outcomes.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder amongst reproductive-aged women associated with cardiometabolic, reproductive and psychological abnormalities. Lifestyle modification, including a healthy diet, is considered first-line treatment for management of clinical symptoms. However, there is limited high-quality evidence to support one superior therapeutic dietary intervention for PCOS management that is beyond general population-based dietary guidelines. Adherence to a Mediterranean diet (MedDiet) has been shown to decrease cardiometabolic disease risk and attenuate depressive symptoms, particularly in patients with metabolic perturbations. This narrative review summarises the proposed biological mechanisms underpinning the potential therapeutic benefits of a MedDiet for the management of cardiometabolic, reproductive and psychological features related to PCOS. Observational evidence suggests an inverse relationship between MedDiet adherence and PCOS features, particularly insulin resistance and hyperandrogenemia. Although the exact mechanisms are complex and multifaceted, they are likely related to the anti-inflammatory potential of the dietary pattern. These mechanisms are underpinned by anti-inflammatory bioactive constituents present in the MedDiet, including carotenoids, polyphenols and n-3 polyunsaturated fatty acids (PUFAs). Synthesis of the available literature suggests the MedDiet could be a promising therapeutic dietary intervention to attenuate short and long-term symptoms associated with PCOS and may aid in reducing the longer-term risks associated with cardiometabolic diseases and reproductive and psychological dysfunction. Nevertheless, current evidence remains insufficient to inform clinical practice and well-designed clinical trials are needed. As such, we provide recommendations for the design and delivery of future MedDiet interventions in women with PCOS, including exploring the acceptability, and feasibility to enhance adherence.

The food we eat has a critical impact on human and planetary health. Food systems are responsible for approximately a third of total global greenhouse gas emissions (GHGE). This review summarises studies that have measured dietary GHGE and assessed their associations with various demographic variables. Most studies report dietary emissions at the individual level, but some studies use households as the unit of analysis. Studies investigating individuals estimate dietary intakes using 24-hour dietary recalls, FFQ, diet history interviews, food diaries or other dietary records. Studies investigating households rely on food purchasing data and expenditure surveys. The majority of studies estimate dietary GHGE using process-based life cycle assessments. It is difficult to directly compare emissions estimates between studies at either the individual or household-level due to methodological differences. In general, there are mixed findings with regard to the relationships between various demographic variables and dietary emissions, although older adults generally had higher dietary GHGE than younger adults, and men typically had higher dietary GHGE than women, even when standardising for total energy intake. This review may be useful in informing and targeting policies and interventions to reduce GHGE of dietary intake.

Endogenous biological rhythms synchronise human physiology with daily cycles of light-dark, wake-sleep and feeding-fasting. Proper circadian alignment is crucial for physiological function, reflected in the rhythmic expression of molecular clock genes in various tissues, especially in skeletal muscle. Circadian disruption, such as misaligned feeding, dysregulates metabolism and increases the risk of metabolic disorders like type 2 diabetes. Such disturbances are common in critically ill patients, especially those who rely on enteral nutrition. Whilst continuous provision of enteral nutrition is currently the most common practice in critical care, this is largely dictated by convenience rather than evidence. Conversely, some findings indicate that intermittent provision of enteral nutrition aligned with daylight may better support physiological functions and improve clinical/metabolic outcomes. However, there is a critical need for studies of skeletal muscle responses to acutely divergent feeding patterns, in addition to complementary translational research to map tissue-level physiology to whole-body and clinical outcomes.

Chrono-medicine considers circadian biology in disease management, including combined lifestyle and medicine interventions. Exercise and nutritional interventions are well-known for their efficacy in managing type 2 diabetes, and metformin remains a widely used pharmacological agent. However, metformin may reduce exercise capacity and interfere with skeletal muscle adaptations, creating barriers to exercise adherence. Research into optimising the timing of exercise has shown promise, particularly for glycaemic management in people with type 2 diabetes. Aligning exercise timing with circadian rhythms and nutritional intake may maximise benefits. Nutritional timing also plays a crucial role in glycaemic control. Recent research suggests that not only what we eat but when we eat significantly impacts glycaemic control, with strategies like time-restricted feeding (TRF) showing promise in reducing caloric intake, improving glycaemic regulation and enhancing overall metabolic health. These findings suggest that meal timing could be an important adjunct to traditional dietary and exercise approaches in managing diabetes and related metabolic disorders. When taking a holistic view of Diabetes management and the diurnal environment, one must also consider the circadian biology of medicines. Metformin has a circadian profile in plasma, and our recent study suggests that morning exercise combined with pre-breakfast metformin intake reduces glycaemia more effectively than post-breakfast intake. In this review, we aim to explore the integration of circadian biology into type 2 diabetes management by examining the timing of exercise, nutrition and medication. In conclusion, chrono-medicine offers a promising, cost-effective strategy for managing type 2 diabetes. Integrating precision timing of exercise, nutrition and medication into treatment plans requires considering the entire diurnal environment, including lifestyle and occupational factors, to develop comprehensive, evidence-based healthcare strategies.

It is estimated that more than one-tenth of adults aged ≥60 years are now classified as having sarcopenic obesity (SO), a clinical condition characterised by the concurrent presence of sarcopenia (low muscle mass and weakness) and obesity (excessive fat mass). Independently, sarcopenia and obesity are associated with a high risk of numerous adverse health outcomes including CVD and neurological conditions (e.g. dementia), but SO may confer a greater risk, exceeding either condition alone. This imposes a substantial burden on individuals, healthcare systems and society. In recent years, an increasing number of observational studies have explored the association between SO and the risk of CVD; however, results are mixed. Moreover, the pathophysiology of SO is governed by a complex interplay of multiple mechanisms including insulin resistance, inflammation, oxidative stress, hormonal shifts and alteration of energy balance, which may also play a role in the occurrence of various CVD. Yet, the exact mechanisms underlying the pathological connection between these two complex conditions remain largely unexplored. The aim of this review is to examine the association between SO and CVD. Specifically, we seek to: (1) discuss the definition, epidemiology and diagnosis of SO; (2) reconcile previously inconsistent findings by synthesising evidence from longitudinal studies on the epidemiological link between SO and CVD and (3) discuss critical mechanisms that may elucidate the complex and potentially bidirectional relationships between SO and CVD.

School food has a major influence on children’s diet quality and has the potential to reduce diet inequalities and non-communicable disease risk. Funded by the UK Prevention Research Partnership, we have established a UK school food system network. The overarching aim was to build a community to work towards a more health-promoting food and nutrition system in UK schools. The network has brought together a team from a range of disciplines, while the inclusion of non-academic users and other stakeholders, such as pupils and parents, has allowed the co-development of research priorities and questions. This network has used a combination of workshops, working groups and pump-priming projects to explore the school food system, as well as creating a systems map of the UK school food system and conducting network analysis of the newly established network. Through understanding the current food system and building network expertise, we hope to advance research and policy around food in schools. Further funding has been achieved based on these findings, working in partnership with policymakers and schools, while a Nutrition Society Special Interest Group has been established to ensure maximum engagement and future sustainability of the network. This review will describe the key findings and progress to date based on the work of the network, as well as a summary of the current literature, identification of knowledge gaps and areas of debate, according to key elements of the school food system.

Anaemia affects more than 36 % of all pregnancies globally and is associated with significant maternal and neonatal morbidity and mortality. Iron deficiency is widely recognised as the most common nutritional cause of anaemia but other nutrient deficiencies are also implicated, including the B vitamin riboflavin, albeit its role is largely under-investigated and thus typically overlooked. Riboflavin, in its co-factor forms flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), is required for numerous oxidation-reduction reactions, antioxidant function and in the metabolism of other B vitamins and iron. While clinical deficiency of riboflavin is largely confined to low-income countries, sub-clinical (functional) deficiency is much more widespread, including in high-income countries, and is particularly common among women of reproductive age and during pregnancy. Limited observational evidence from high-income populations suggests that suboptimal riboflavin status contributes to an increased risk of anaemia. Furthermore, randomised controlled trials in pregnant women from low- and middle-income countries have demonstrated beneficial effects of riboflavin on haematological status and anaemia. Various mechanisms have been proposed to explain the contribution of riboflavin deficiency to anaemia, with the strongest evidence pointing to an adverse effect on iron metabolism, given that riboflavin co-factors are required for the release of iron from storage ferritin in the production of red blood cells. Overall, this review investigates riboflavin intakes and status during pregnancy in different populations and evaluates the available evidence for the under-recognised role of riboflavin in the maintenance of haemoglobin concentrations together with its potential to protect against the development of anaemia during pregnancy.

Gestational diabetes mellitus (GDM) poses significant health concerns for women and their offspring, with implications that extend beyond pregnancy. While GDM often resolves postpartum, a diagnosis of GDM confers a greater risk of future type 2 diabetes (T2D) and other chronic illnesses. Furthermore, the intergenerational impact of GDM predisposes offspring to increased chronic disease risk. Despite the awareness of the short- and long-term consequences of GDM, translating this knowledge into prevention strategies remains challenging. Challenges arise from a lack of clarity among health professionals regarding roles and responsibilities in chronic disease prevention and women’s lack of awareness of the magnitude of associated health risks. These challenges are compounded by changes in the circumstances of new mothers as they adjust to balance the demands of infant and family care with their own needs. Insights into behaviour change strategies, coupled with advances in technology and digital healthcare delivery options, have presented new opportunities for diabetes prevention among women with a history of GDM. Additionally, there is growing recognition of the benefits of adopting an implementation science approach to intervention delivery, which seeks to enhance the effectiveness and scalability of interventions. Effective prevention of T2D following GDM requires a comprehensive person-centred approach that leverages technology, targeted interventions and implementation science methodologies to address the complex needs of this population. Through a multifaceted approach, it is possible to improve the long-term health outcomes of women with prior GDM.

In 2023, the UK government announced a Major Conditions Strategy, publishing ‘The case for change and our strategic framework’, which set out the focus on cancers, diabetes, dementia, mental ill health, musculoskeletal disorders, CVD and chronic respiratory diseases. Together, these conditions account for 60% of total disability-adjusted life years lost to early death or ill health in England, and one in four adults has at least two (multimorbidity). This review considers some of the key dietary risks for these major conditions and population policies that may improve diets and reduce risks. UK Government dietary recommendations, based on independent risk assessment and advice from the Scientific Advisory Committee on Nutrition, are encapsulated in the national food model, the Eatwell Guide. Based on key sources of dietary data – chiefly consumption data from the National Diet and Nutrition Survey and consumer purchase data from Kantar – most people do not meet dietary recommendations. This review considers how science and evidence inform health improvement policy. This includes policies that encourage healthier food choices, such as labelling and public procurement standards to those that minimise the impact of the less healthy choice such as sugar and salt reduction and reformulation. The review also considers nutritional approaches to managing some non-communicable diseases. Given the role nutrition and excess weight play in the onset, prognosis and quality of life for those living with one or more of the major conditions, there are huge potential gains from even small dietary improvements across population groups.

The gastrointestinal (GI) tract plays a critical role in nutrition and the pathophysiology of disease, and there is an increasing variety of methodologies available for the assessment of various aspects of GI physiology. Advancements in assessment methods, including techniques to study gut motility, fermentation, permeability, and microbiota composition, have provided researchers with powerful tools to investigate the impact of diet on GI tract physiology and the microbiota-gut-brain axis. Mechanistic evidence from reverse translational studies, which apply findings from human studies to preclinical models in a ‘bedside-to-bench’ approach, have also enhanced our understanding of the bidirectional interactions and candidate signalling molecules among the diet-gut-brain relationship. Interpreting data from these advanced techniques and study designs requires a thorough understanding of their principles, applications, and limitations. This review aims to summarise the methodological advances in GI tract physiology measurements and their application in nutritional studies, focusing on gut motility, fermentation, and permeability. We will present examples of how these techniques have been utilised in recent research, discuss their advantages and limitations, and provide insights on their use and interpretation in research. Understanding the capabilities and limitations of these tools is crucial for designing robust studies and elucidating the complex interplay between diet and the GI tract. The scope of this review encompasses recent advancements in GI tract assessment methodologies and their implications for nutritional research, providing a comprehensive overview for researchers in the field.

Musculoskeletal disorders and age-related musculoskeletal decline are major contributors to the burden of ill health seen in older subjects. Despite this increased burden, these chronic disorders of old age receive a relatively small proportion of national research funds. Much has been learned about fundamental processes involved in ageing from basic science research and this is leading to identification of key pathways that mediate ageing which may help the search for interventions to reduce age-related musculoskeletal decline. This short review will focus on the role of reactive oxygen species in age-related skeletal muscle decline and on the implications of this work for potential nutritional interventions in sarcopenia. The key physiological role of reactive oxygen species is now known to be in mediating redox signalling in muscle and other tissues and ageing leads to disruption of such pathways. In muscle, this is reflected in an age-related attenuation of specific adaptations and responses to contractile activity that impacts the ability of skeletal muscle from ageing individuals to respond to exercise. These pathways provides potential targets for identification of logical interventions that may help maintain muscle mass and function during ageing.

The relationship between nutrition and ageing is complex. The metabolism and synthesis of micronutrients within the gut microbiome can influence human health but is challenging to study. Furthermore, studying ageing in humans is time-consuming and difficult to control for environmental factors. Studies in model organisms can guide research efforts in this area. This review describes how the nematode Caenorhabditis elegans can be used to study how bacteria and diet influence ageing and inform follow-on studies in humans. It is known that certain bacteria accelerate ageing in C. elegans. This age-accelerating effect is prevented by inhibiting folate synthesis within the bacteria, and we propose that in the human microbiome, certain bacteria also accelerate ageing in a way that can be modulated by interfering with bacterial folate synthesis. Bacterial-derived folates do not promote ageing themselves; rather, ageing is accelerated by bacteria in some way, either through secondary metabolites or other bacterial activity, which is dependent on bacterial folate synthesis. In humans, it may be possible to inhibit bacterial folate synthesis in the human gut while maintaining healthy folate status in the body via food and supplementation. The supplement form of folic acid has a common breakdown product that can be used by bacteria to increase folate synthesis. Thus, supplementation with folic acid may not be good for health in certain circumstances such as in older people or those with an excess of proteobacteria in their microbiome. For these groups, alternative supplement strategies may be a safer way to ensure adequate folate levels.

Oceania is currently facing a substantial challenge: to provide sustainable and ethical food systems that support nutrition and health across land and water. The Nutrition Society of Australia and the Nutrition Society of New Zealand held a joint 2023 Annual Scientific Meeting on ‘Nutrition and Wellbeing in Oceania’ attended by 408 delegates. This was a timely conference focussing on nutrition challenges across the Pacific, emphasising the importance of nutrition across land and water, education settings, women’s health and gut health. Cutting-edge, multi-disciplinary and collaborative research was presented in a 4-day programme of keynote presentations, workshops, oral and poster sessions, breakfast and lunch symposiums and early career researcher sessions. The conference highlighted the importance of collaboration between nations to address the challenge facing nutrition and wellbeing across Oceania. A systems approach of collaboration among scientists, industry and government is vital for finding solutions to this challenge.

Loss of skeletal muscle strength and mass (sarcopenia) is common in older adults and associated with an increased risk of disability, frailty and premature death. Finding cost-effective prevention and treatment strategies for sarcopenia for the growing ageing population is therefore of great public health interest. Although nutrition is considered an important factor in the aetiology of sarcopenia, its potential for sarcopenia prevention and/or treatment is still being evaluated. Nutrition research for sarcopenia utilises three main approaches to understand muscle-nutrition relationships, evaluating: single nutrients, whole foods and whole diet effects – both alone or combined with exercise. Applying these approaches, we summarise recent evidence from qualitative and quantitative syntheses of findings from observational and intervention studies of healthy older adults, and those with sarcopenia. We consider protein supplements, whole foods (fruits and vegetables) and the Mediterranean diet as exemplars. There is some evidence of beneficial effects of protein supplementation ≥ 0·8 g/kg body weight/d on muscle mass when combined with exercise training in intervention studies of healthy and sarcopenic older adults. In contrast, evidence for effects on muscle function (strength and physical performance) is inconclusive. There is reasonably consistent epidemiological evidence suggesting benefits of higher fruits and vegetables consumption for better physical performance. Similarly, higher adherence to the Mediterranean diet is associated with beneficial effects on muscle function in observational studies. However, intervention studies are lacking. This review discusses how current evidence may inform the development of preventive and intervention strategies for optimal muscle ageing and nutritional public policy aimed at combatting sarcopenia.

The practice of antenatal colostrum expression (ACE), or the extraction of colostrum from the breasts during pregnancy, has an interesting history and continues to evolve. This narrative review aims to describe how perception and practices of ACE have changed over time, summarise the evidence on ACE in maternal and infant care, and highlight areas for future research. The literature demonstrates that ACE is safe for low-risk women when done from around 36 weeks’ gestation. Women should be reassured that the skill of hand expressing is a valuable tool post-birth, regardless of whether they are able to collect colostrum antenatally or not. The collection and storage of colostrum in pregnancy can help avoid formula use in hospital, which may have follow on effects immune function and other areas. Ideally, colostrum collected during pregnancy would be kept safely frozen during the hospital stay and only defrosted and used during the stay if medically indicated, with parents supported through that process. Although ACE does not appear to improve long-term breastfeeding rates at present, it can increase confidence around breastfeeding. Further research in more diverse population groups, long-term breastfeeding and long-term health outcomes of using frozen antenatally expressed colostrum for babies (as compared to formula or fresh colostrum) would be valuable to gain a better understanding of the importance of ACE in maternity care.

Folate, vitamin B12, vitamin B6 and riboflavin interact by functioning as cofactors within one-carbon metabolism (OCM), a network of interrelated cellular pathways essential for numerous biological processes, including the biosynthesis of DNA, amino acid interconversions and methylation reactions. The pathways of OCM are influenced by endocrine signals and genetic polymorphisms and are particularly responsive to relevant B-vitamin intakes. Physiological changes in healthy pregnancy, leading to a steady decline in B-vitamin status, add another layer of complexity to the regulation of OCM. Although significant advances have been made to improve our understanding of these pregnancy-related changes, no specific reference ranges yet exist for B-vitamin biomarkers in pregnancy to support normal fetal growth without depleting maternal stores. The lack of pregnancy-related criteria for adequacy of B-vitamin status is in turn a major limitation in identifying pregnant women most at risk of B-vitamin deficiency. Another challenge is that the evidence is very limited to provide a basis for establishing pregnancy-specific dietary recommendations for B-vitamins to support successful pregnancy outcomes. In terms of preventing adverse outcomes, periconceptional folic acid supplementation has a proven role, established more than 30 years ago, in protecting against neural tube defect-affected pregnancies and this has been the major focus of public health policy worldwide. This review evaluates the emerging evidence for the less well recognised role of B-vitamins in preventing hypertensive disorders in pregnancy and the intergenerational effects of B-vitamins on offspring neurodevelopment and cognitive performance during childhood. We also consider the underlying biological mechanisms.